| Message ID | 20170302123746.9694-2-berrange@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 03/02/2017 06:37 AM, Daniel P. Berrange wrote: > Some of the migration parameters are strings, which default to NULL, > eg tls-hostname and tls-creds. > > The mgmt app will set the tls-creds parameter on both source and target > QEMU instances, in order to trigger use of TLS for migration. > > After performing a TLS encrypted migration though, migration might be > used for other reasons - for example, to save the QEMU state to a file. > We need TLS turned off when doing this, but the migrate-set-parameters > QAPI command does not provide any facility to clear/reset parameters > to their default state. > > If you simply omit the tls_creds parameter in migrate-set-parameters, > then 'has_tls_creds' will be false and so no action will be taken. JSON > allows a parameter to have a nil value, but the QEMU JSON visitor will > reject that when deserializing into a QObject. > > The migration code has no need to distinguish "" vs NULL for the TLS > hostname or TLS credentials object name, since "" is invalid in both > cases. This enables clearing of tls-hostname and tls-creds by > treating "" as equivalent to NULL. It's also worth documenting in the .json file that "" is special-cased. But the C code change looks okay (with your explanation on v1 that the has_* parameters are not used internally). > > Signed-off-by: Daniel P. Berrange <berrange@redhat.com> > --- > migration/migration.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/migration/migration.c b/migration/migration.c > index c6ae69d..a8cb56e 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -872,11 +872,19 @@ void qmp_migrate_set_parameters(MigrationParameters *params, Error **errp) > } > if (params->has_tls_creds) { > g_free(s->parameters.tls_creds); > - s->parameters.tls_creds = g_strdup(params->tls_creds); > + if (*params->tls_creds == '\0') { > + s->parameters.tls_creds = NULL; > + } else { > + s->parameters.tls_creds = g_strdup(params->tls_creds); > + } > } > if (params->has_tls_hostname) { > g_free(s->parameters.tls_hostname); > - s->parameters.tls_hostname = g_strdup(params->tls_hostname); > + if (*params->tls_hostname == '\0') { > + s->parameters.tls_hostname = NULL; > + } else { > + s->parameters.tls_hostname = g_strdup(params->tls_hostname); > + } > } > if (params->has_max_bandwidth) { > s->parameters.max_bandwidth = params->max_bandwidth; >
diff --git a/migration/migration.c b/migration/migration.c index c6ae69d..a8cb56e 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -872,11 +872,19 @@ void qmp_migrate_set_parameters(MigrationParameters *params, Error **errp) } if (params->has_tls_creds) { g_free(s->parameters.tls_creds); - s->parameters.tls_creds = g_strdup(params->tls_creds); + if (*params->tls_creds == '\0') { + s->parameters.tls_creds = NULL; + } else { + s->parameters.tls_creds = g_strdup(params->tls_creds); + } } if (params->has_tls_hostname) { g_free(s->parameters.tls_hostname); - s->parameters.tls_hostname = g_strdup(params->tls_hostname); + if (*params->tls_hostname == '\0') { + s->parameters.tls_hostname = NULL; + } else { + s->parameters.tls_hostname = g_strdup(params->tls_hostname); + } } if (params->has_max_bandwidth) { s->parameters.max_bandwidth = params->max_bandwidth;
Some of the migration parameters are strings, which default to NULL, eg tls-hostname and tls-creds. The mgmt app will set the tls-creds parameter on both source and target QEMU instances, in order to trigger use of TLS for migration. After performing a TLS encrypted migration though, migration might be used for other reasons - for example, to save the QEMU state to a file. We need TLS turned off when doing this, but the migrate-set-parameters QAPI command does not provide any facility to clear/reset parameters to their default state. If you simply omit the tls_creds parameter in migrate-set-parameters, then 'has_tls_creds' will be false and so no action will be taken. JSON allows a parameter to have a nil value, but the QEMU JSON visitor will reject that when deserializing into a QObject. The migration code has no need to distinguish "" vs NULL for the TLS hostname or TLS credentials object name, since "" is invalid in both cases. This enables clearing of tls-hostname and tls-creds by treating "" as equivalent to NULL. Signed-off-by: Daniel P. Berrange <berrange@redhat.com> --- migration/migration.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)